Module:Library work multi-author

local p = {}

local function formatList(items)
    local count = #items
    if count == 0 then
        return ""			-- returns nothing if empty
    elseif count == 1 then
        return items[1]		-- just return the string input if alone
    elseif count == 2 then
        return items[1] .. " and " .. items[2]		-- returns "string1, string2, ... and last_string"
    else
        local last = table.remove(items)
        return table.concat(items, ", ") .. " and " .. last
    end
end

function p.main(frame)
    local args = frame:getParent().args
    local items = {}
    
    for _, value in pairs(args) do
        if value ~= '' then
            table.insert(items, value)
        end
    end
    
    return formatList(items)
end

function p.link(frame)
    local args = frame:getParent().args
    local items = {}
    
    for _, value in pairs(args) do
        if value ~= '' then
            local title = mw.title.new(value)		-- creates object for page
            if title and title.exists then			-- checks if page exists
                table.insert(items, "[[" .. value .. "]]")	-- adds to the item table with wikilink format
            else
                table.insert(items, value)				-- page doesn't exist, adds to the item table without the wikilink format
            end
        end
    end
    
    return formatList(items)
end

return p